


Undyne seduces a swimmer girl

by morefishplease



Series: Comfy Fish Stories [38]
Category: Undertale (Video Game)
Genre: F/F, Lesbian Sex, Oral Sex, Seduction, Swimming Pools
Language: English
Status: Completed
Published: 2017-04-23
Updated: 2017-04-23
Packaged: 2018-10-22 20:49:29
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,137
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10704822
Author URL: https://archiveofourown.org/users/morefishplease/pseuds/morefishplease
Summary: What it says in the title. Due to having originally been written and posted for a different site most of my stories' titles are just descriptions of the story, and I'm too lazy to make up meaningful titles for everything.





	Undyne seduces a swimmer girl

Brill can feel the fish-girl’s eyes on her as she rebounds off the back wall, flips onto her back for another lap. She’s been staring all night from her perch high up on the lifeguard chair, lounging there, one foot over the chair’s arm. One time when Brill paused for a quick break, eyeing the other swimmers splashing around her, sending clamoring echoes flying to the pool’s roof, she chanced a glance over at Undyne and met her stare for stare until those brilliant golden eyes made her flinch back, flip her goggles back down, dive again into the pool. Her ribs ached but her stomach had done a little curvy flip in on itself when she saw Undyne staring at her, saw her impassive mouth widen into a toothy grin.

Undyne blows the whistle and Brill slows in the water, comes to a stop. She looks over, flips her goggles off, sees Undyne has slid her lithe body down from her chair, come to the edge of the pool. “Yeah?” Brill calls.

“Pool’s closing,” Undyne purrs, running her eyes over Brill’s lanky body. Brill can feel Undyne’s gaze like a wave of ticklish pressure passing over her, lingering, she notices, on her small handful-breasts, on her wide hips, on her taut thighs.

Ever since she’d started swimming here Brill had kept an eye on the tall, muscular lifeguard. It was something, she had decided upon introspection, about the way she moves, both in the water and on land. On land she’s dense and strong and solid, the sort of walk that a karateka has, ready to pounce. In the water, though, Undyne is graceful and blazing quick; Brill is a decently fast swimmer but Undyne could outstrip her without breaking a sweat, beating the water into submission with those powerful legs. Brill can never help but stare for a moment, as soon as she comes in, run her gaze over Undyne’s slim, pretty face, her muscular neck, (her firm breasts)…

“Think I can take two more laps?” Brill asks, beaming her toothiest grin at Undyne. “I’m almost done.”

“You’ve been swimming for two hours,” Undyne notes, raising an eyebrow. Brill feels a flush flood into her cheeks, sees Undyne grin wider. “Tell you what,” Undyne says, a predatory note in her voice that makes the hairs on Brill’s arms stand on end, “I’ll let you have those two laps –“

“Thanks, I’ll –“

“- if,” Undyne continues, raising a clawed finger, “you do something for me first.”

A lightning bolt strikes somewhere in Brill’s stomach and she cannot speak for a moment. She finally manages to stutter out a shaky ‘um, s-sure –“ but Undyne talks over her, slipping into the water like a knife and paddling slowly near her.

“I’ve seen the way you’ve been looking at me,” Undyne hisses seductively, the words like snakes spitting at Brill’s face, “I know what you want.”

“I don’t –“

“Don’t play dumb,” Undyne growls in Brill’s ear, and she jumps – how has she gotten so close so quickly? The fish-girl is mere inches away from her now and Brill can see everything, absolutely everything – from the way her skin is slick like oil, the way the corners of her mouth are twitching with barely suppressed mirth or lust, the way her gills are puffing out into miniature constellations of flowers, the way her arms are slipping around Brill’s slender waist –

Brill’s cheeks are burning furiously and she can’t seem to meet Undyne’s eyes. She  feels terribly exposed, floating there in the middle of the pool. “Maybe we s-should –“ Brill begins but Undyne silences her with a long, passionate kiss, running her rough tongue lightly over Brill’s teeth, over the roof of her mouth. She feels herself moaning with longing against her will and all of a sudden there is a terrible heat building between her legs. She grabs Undyne furiously, presses herself against the fish-girl desperately, and feels Undyne chuckle into her mouth, their lips still locked together. She bites Undyne’s lip and is rewarded with an aroused grunt as Undyne slips Brill’s swimsuit down, lays a hand across Brill’s breast, tweaks her nipple. A lance of pleasure strikes through Brill and all resistance slips out of her, all at once. She needs more, desperately. She’s fumbling with Undyne’s swimsuit, although her distraction has made her clumsy, and Undyne chuckles throatily, unzips herself for Brill, and those breasts she’d been eyeing for days burst free. She buries her head in Undyne’s bosom, takes one of the fish’s nipples into her mouth, and Undyne lets out a long rattling moan as she snakes her hand downward to Brill’s sopping-wet crotch. When she lays her hand over Brill, squeezes lightly, Brill thrusts forward with her hips subconsciously, driving the tip of Undyne’s finger into her through her swimsuit. She gasps and Undyne grabs her, drags her in again for another kiss. She can feel Undyne’s legs kicking steadily, keeping them afloat as Undyne slowly slides Brill’s swimsuit aside, runs her finger over Brill’s clit and is rewarded with a shudder. Undyne’s finger runs in a slow semicircle around Brill’s moistening entrance, then plunges inside. Brill moans, bucks against Undyne’s finger as the fish-girl slowly fucks her, first gently, then with increasing abandon as Undyne’s own lust grows. Undyne has reached out with her other hand, took ahold of Brill’s head, kept them locked, foreheads touching. Brill can’t take the intensity of Undyne’s lustridden stare and keeps her eyes on Undyne’s breasts.

When Brill comes it is with a small cry, a shudder in her hips, an unfamiliar name on her lips. Undyne kicks them over to the edge of the pool, pulls herself up, holds onto Brill tightly as Brill bites her lips, rides out the aftershocks of the orgasm. She lays her head on Undyne’s thigh, rests for a moment, but soon a strong, sharp smell like pepper and sugar spikes into her nostrils and she blinks blearily, comes face to face with Undyne’s dripping-wet slit.

“My turn,” Undyne purrs, taking a firm grip on Brill’s head, and she laps eagerly, running her tongue in circles over Undyne’s sweet-tasting clit. Her juices are thick and strong and Brill finds herself growing aroused again, even though she’d only came a moment ago. Undyne is moaning and shaking as Brill prods her tight opening with her tongue, but she pops a golden eye open, watches Brill clutching at her own breast, and Undyne grins in between the waves of pleasure washing over her. She pulls Brill back for  a moment, dives down, turns herself around, presses Brill back between her legs.

As Undyne’s tongue runs over her clit Brill shudders, presses herself against Undyne eagerly, desperately. Before she is entirely lost to lust, she manages to think “maybe I’ll skip the two laps after this.”

**Author's Note:**

> Oh man, Brill. Brill is probably the character in this whole series that I'm the most pleased with, just due to the dynamic between her and Undyne. It's a little less obvious in this story but I develop on it pretty quickly, and essentially what I was trying to do with Brill was give Undyne a reason to play. If the dynamic with 'you' is fairly evenly matched and the dynamic with Alphys is more protective, Brill gives Undyne an opportunity to be playful. The image I had in my head was of a mother cat playing with her kittens - there's the sense of a deigned sacrifice of power in either situation.
> 
> The question I anticipate is 'if you're going to write lesbian stuff with Undyne, why not just use Alphys?' There are two answers, the first being that the request was for Undyne x female human, and of course the second is that there are some things Alphys simply can't offer when you're writing her, not if you want to stay in character...like confidence, and so on. Sometimes I wish I could just write a novel-length thing about Undyne so that I could write her as a lot less of a slut than she is in this series. I have the length all down, this series is about 200k words in total, give or take, but that's a consequence of just doing requests. People either want sappy stuff or erotic stuff, and you have to make the choice between in-depth things that work in everything you want to work in, or quick things at a decent level of quality. I think the latter is the better choice.
> 
> Brill was, at least physically, based on my then-ex-girlfriend. We've since gotten back together and she was very amused when she read these stories featuring Brill. I don't recall why I made that choice, but it wasn't for catharsis or anything; I think it's because I'm very comfortable with her body and how it feels, so I could write about it more easily.
> 
> I chose the name 'Brill' for two reasons, one because it's unconventional and draws the eye, and secondly because it's the name of a type of flatfish and I thought that the symmetry fit nicely.
> 
> I'm a little dissatisfied with this ending, it feels a little like a cop-out to me and looking back on it now I wish I'd kept going, in light of how significant a character Brill would end up being.


End file.
